Autonomous vehicles and moral judgments under risk

Some criticize the data-driven study of driverless car ethics for relying on deterministic crash scenarios where the focus should be on minimizing the occurrence of accidents instead. Indeed, decisions in road traffic are taken in the domain of risk. A relevant ethical question is, however, whether autonomous vehicles should actually minimize an accident’s probability or rather balance the accident’s probability and severity. While ethicists’ introspections might lead them to different conclusions, a participatory paradigm in ethics demands to include laypeople’s intuitions into the societal debate. In three online studies, we found that the mere minimization of accident probability in ethical dilemmas does not correspond to the views of our sample. Our participants favor a balanced consideration of accident probability and severity. This remains true even if the underlying dilemma is based on a more realistic scenario of allocating minor risks among road users. Our findings furthermore illustrate that trolley problems may be informative for autonomous vehicles and emphasize the importance of transparency if manufacturers and the public do not agree on guiding principles in road traffic.